Refrigerating apparatus



July 12, 1932. J. R. KILLEN REFRIGERATING APPARATUS Filed April 30, 1930 v P t -smu .12, 1932,

v UNITED STATES,

JAMES R. KILLEN,

PATENT OFFI BEFBIGERATING APPARATUS Application filed April 30;

' is to provide an improved evaporator of the type which is relatively long horizontally and relatively narrow vertically.

' Another object of the invention is to provide a relatively long and relatively narrow evaporator of the flooded type in which it is "necessary to use only a comparatively small amount of liquid refrigerant.

A further object is to prevent oil logging of horizontally extending ducts of a flooded type evaporator and to prevent liquid refrigerant from passing from the evaporator.

More specifically it, is an ob ect of the present invention to provide for a free space directly above the liquid refrigerant throughout the length of an' elongated evaporator of the flooded type.

ash Further objects and advantages of the pres.

. ent invention will be apparent from the following description, reference being had to t e accompanying drawing, wherem a preferredform of the present mvention is clearly shown.

In the drawing:

Fig. 1 is a rear view of a display type of refrigerator, partly in section, the section being taken on line 1--1 of Fig. 2 and showing my improved evaporator therein;

Fig. 2 is a sectional view taken on line 22 of Fig.1;

Fig. 3 is a top plan view of the improved evaporator;

' Fig. 4 isa side view thereof; and

Fig. 5 is a sectional view taken on line 55 of Fig. 4. 0

The present invention deals principally with evaporators that are relatively long horizontally and relatively narrow vertically and the particular evaporator, shown for illustrative purposes only, is illustrated in connection with a display case having a rela- 1930. Serial No. 448,540.

ment 22. In the latter certain parts of refrigerating apparatus may be enclosed or it may be used for a storage chamber. At the ower part and to the rear of the storage compartment 21 there is provided a cooling chamber or compartment 24 for receiving the evaporator 25. This evaporator is supported on brackets 26 so as to provide a space below same and is proportioned so as to be spaced from the upper part of the compartment 24. A bafile 28 causes the air which enters the compartment 24 to circulate through the evaporator before it leaves the compartment.

The evaporator is of the flooded type and is herein shown asthe type in which the quantity of refrigerant therein is controlled by a float on the low pressure side of the system.

[Referring particularly to Fig. 4, the evaporator comprises a header or tank 30 form a reservoir for liquid refrigerant. Liquid refrigerant is led to the evaporator through a coupling 31 and is withdrawn therefrom through a coupling 32. These couplings are carried by a removable head 33. The flow of refrigerant from a condenser of the refrigerating system through the coupling 31 and into the header 30 is controlled by a float 34 contained within the header 30. This float actuates a needle valve 35.to prevent further flow of liquid refrigerant into the evaporator when a predetermined liquid level is attained within the header. The outlet of the header is in the form of a tube 37 which extends into 0F DAYTON, OHIO, A SSIGNOB TO FRIGIDAEE CORPORATION, 01" DAYTON, OHIO, A CORPORATION OF DELAWARE dering. These flattened ducts provide tal-l narrow refrigerant chambers and the ar- 1s below the upper part of the tall duct so as to provide a gas chamber or free space rangement is such that the liquid refrigerant above the liquid in the ducts. The ends of ducts, opposite the header 30, are sealed as at In addition to increasing the heat transfer surface of the ducts 40, the fins 43 increase the strength of the evaporator. The ducts 40 bein tall and narrow will tend to bulge outwar 1y when an excessive pressure is present within the evaporator. In the particular arrangement the ducts 40 extend through slots within the fins 43 and these slots are substantially the same dimensions as: the outside dimensions of the tube. These fins are preferably soldered to the duct so as to closely embrace the ducts and thereby prevent bulging of same and so as to provide a good heat transfer relation betweensame. Due to the shape of the ducts, a comparatively small amount of refrigerant is brought in contact with a relatively large heat transfer section of transversely disposed fins.

In refrigerating systems of the type in which oil floats upon the refrigerant within the evaporator, for example, when S0 is used as a refrigerant, this oil tends to collect in certain places and prevent the flow of refrigerant whereby some portions of the evaporator do not function properly. Also the oil tends to form'in a thick blanket upon the refrigerant and causes what is known as bumping within the evaporator namely, the blanket prevents the boiling of therefrigerant until the refrigerant is super-heated and then an explosion takes place within the evaporator. Under such conditions, liquid refrigerant will be conveyed out of the evaporator causing refrigeration to take place in the outlet pipe of the evaporator and' at times causes liquid refrigerant to be delivered to the compressing mechanism. In accordance with the present invention, I prevent the collection of a thick blanket'of oil on the refrigerant by providing a free surface for the escape of gas throughout the length of the evaporator. This free surface is indicated at 44: above the oil level 45. The liquid refrigerant level is shown at 46. By this arrangement the gas bubbles may flow in their natural manner namely, upwardly, and due to the constant ebullition, a quantity of oil is carried with the gas bubbles into the free space whence it is delivered through the outlet 37 to the compressor. By constant- 1y withdrawing a quantity of oil with the gas only a small layer of oil will-collect upon the evaporator.

In addition to the advantages above set forth the evaporator herein disclosed can be manufactured at a low cost since it can be readily assembled because of the necessity of only a few tubes and only a few soldered joints.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other .forms might be adopted, all coming within frigerant, a tall narrow refrigerant duct extending horizontally from the reservoir, said duct having its lower portion connected below the liquid refrigerant level and its upper portion with the free space above the liquid,

and fin means thermally connected with said uct.

2. An evaporator for a mechanical refrigerator comprising a reservoir for liquid refrigerant, a tall narrow refrigerant duct extending horizontally from the reservoir, said duct having its lower portion connected below the liquid refrigerant level and its upper portion with the free space above the liquid, and a lurality of fins arranged transversely of sfiiitfduct and thermally connected therewit 3. An evaporator for a mechanical refrigerator comprising a reservoir for liquid refrigerant, a tall narrow refrigerant duct extending horizontally from the reservoir,

means for maintaining the refrigerant level intermediate the top and bottom of said duct, and fin means thermally connected with said uct.

4. An evaporator-for a mechanical refrigerator comprising a reservoir for liquid refrigerant, a tall narrow refrigerant duct extending' horizontally from the reservoir,

erant level and its upper portionwith the free space above the liquid, and fins connected with said ducts and bridging the space between same.

6. An evaporator for a mechanical refrigerator comprisin a reservoir for liquid refrigerant', a plura ity of tall narrow refriger ant ducts extending horizontally from the reservoir, said ducts each having its lower portion connected below the liquid refrigerant level and its upper portion with the free space above the liquid, and a plurality of fins arranged transversely of said ducts, said fins bein thermally connected with said ,ducts and bridging the space between same.

7 An evaporator for a mechanical refrigerator comprising a reservoir for liquid refrigerant, a plurality of tall narrow refrigerant ducts extending horizontally from the reservoir, means for maintaining the refrigerant level intermediate the top and bottom of said ducts, and connected with said ducts and bridging the space between same 8, An evanorator for a mocha ical refrig- 5 erator comprising a reservoir for liquid re frigerant, a glurality oi? tall narrow refrigerant ducts extending horizontally from the reservoir, means for maintaining the refrigerant level intermeciate the top and bottom w or ducts, and a plurality of tins arranged transversely of said ducts, said fins being thermally connected with said ducts and bridging the space between same.

An evaporator for a mechanical refrig 15 orator comprising a reservoir for liquid reirigerant, a tall, narrow refrigerant duct extending horizontally from the reservoir, and means for maintaining the refrigerant level intermediate the top and bottom of said 2g duct, said duct having a relatively large contacting surface in proportion to the volume of refrigerant contained therein,

16. An evaporator for a mechanical re frigerator comprising a reservoir for liquid 35 reirigerant, a plurality of tall, narrowre irigerant ducts extending horizontally from the reservoir, said ducts each having its lower portion connected below the liquid refrigerant level and its upper portion with so the free space above the liquid, said ducts having a relatively large amount of contacting surface in proportion to the volume of refrigerant contained therein.

ll. An evaporator comprising a plurality :35 of horizontally extending, tall, narrow and parallel ducts, each duct having parallel upright sides, a fin means bridging all of said ducts, said in means being arranged substantially perpendicular to and in a plane trans- 18 verse to the longitudinal axis of the ducts.

' 12. An evaporator comprising a plurality of horizontally extending, tall, narrow and parallel refrigerant conveying ducts, a plurality of strip fins, each hn bridging all of 45 said ducts, said fins being arranged substantially perpendicular to and in a plane transverse to the longitudinal axis of the ducts.

13.. In combination with a refrigerator designed for the circulation of air in a given to direction, an evaporator located within said refrigerator, said evaporator comprising a plurality of tall, narrow and parallel refrigerant conveying ducts, a plurality of strip fins, each fin bridging all of said ducts, said 5 evaporator being arranged Within said refrigerator so that the fins are parallel to the path of circulating air within the refrigerator and said fins being also substantially perpendicular to and in a plane transverse to the longitudinal axis of the ducts.

In testimony whereof I hereto alfix my signature.

JAMES R. KILLEN. 

